Mountain of ... bluster

President Barack Obama's decision to put the kibosh on the Yucca Mountain nuclear waste repository has been a favorite punching bag for House Republicans in recent weeks, thanks in part to the debacle at Japan's Fukushima Daiichi power plant stoking fears over the safety of nuclear waste stored at more than 100 temporary sites around in the country (map). “It is unconscionable for the Obama administration to squander three decades of bipartisan collaboration, breakthrough scientific research, and billions of taxpayer dollars, all for what the GAO has determined to be political calculations," Energy and Commerce Committee leaders Fred Upton (R-MI) and John Shimkus (R-IL) proclaimed in a joint statement Friday. "This administration should be listening to the nuclear scientists, not political scientists, on matters as serious as our nuclear future."

Upton and Shimkus were referring to a lengthy document (pdf), released last week by the Government Accountability Office, which concluded that the Department of Energy shut down the project for policy reasons, rather than technical ones, and did so in a way that would make it exceedingly difficult and expensive to restart should it be necessary to do so. "The Secretary’s judgment," the DOE apparently wrote to the Nuclear Regulatory Commission in its request to stop the application, "is not that Yucca Mountain is unsafe or that there are flaws in the license application, but rather that it is not a workable option and that alternatives will better serve the public interest.”

But even if Yucca's shutdown was politically motivated (Obama's promise to do so is undoubtedly part of why he was able to take Nevada, where the repository would have been located, in the 2008 presidential election), lawmakers would do good to remember that its selection was overtly political as well. (And not, as Upton and Shimkus assert, determined simply through happy, hand-holding collaboration and breakthrough scientific research). In her 2009 HCN feature, "Mountain of Doubt," contributing editor Judith Lewis Mernit did a great job summing it up:

Fearing the collapse of a faltering (nuclear) industry, Congress in 1982 drew up the Nuclear Waste Policy Act, ordering the Energy Department to open a nuclear waste storage facility within 16 years. But Congress did nothing in that time except select Yucca Mountain as the only location worth studying -- not least because the federal government already controls 90 percent of Nevada's land -- delaying until 2002 to give the site final approval and allow the Energy Department to at long last apply for a license...

Yucca Mountain, as New York Times reporter Matthew Wald recently joked to (the Bush Administration's top shepherd of the project, Ward) Sproat, "was chosen by some of the best geologists in the U.S. Senate," many of whom were rushing home for Christmas break when they ruled. Even Sproat calls the site selection "a technically informed political decision."

There were more than a few technical reasons to look beyond Yucca as well, Lewis Mernit continues:

Six hundred earthquakes have rumbled under Yucca Mountain in the last 20 years, one as great as magnitude 5.6. A panel of scientists put the chances of "igneous disruption" in the ridgeline's ancient field of volcanoes at one in 6,250 over the next 10,000 years — which seems low until you consider that, in most of the United States, the probability of a volcano erupting is zero.

If anything, though, shouldn't the disaster at Fukushima drive home the foolishness of putting all of our waste -- tens of thousands of tons of it from 104 nuclear reactors -- in one potentially seismically unstable place just 90 miles from Las Vegas, especially when that place is supposed to provide safe storage for 1 million years? And why should Nevada, which has already had the unfortunate privilege of hosting the nation's nuclear bombing range, bear the burden of its nuclear waste problem?

In this context, the recently released draft recommendations of the Blue Ribbon Commission on America's Nuclear Future make some sense. The commission, convened by the Obama Administration to identify possible solutions for the nation's nuclear waste problem in the wake of the Yucca closure, suggested that storing waste for 100 years or so at one or more above-ground interim sites, located regionally and perhaps closer to the reactors that produced the waste, could dispel some of the political backlash, buy time to find a more suitable long term site and open up the possibility of reprocessing and reusing the waste down the line. "We may decide later that it's an energy source and we want to do something with it," commissioner Ernest Moniz, a physicist at the Massachusetts Institute of Technology, told ScienceInsider.

But regardless of what eventually shakes out, as Lewis-Mernit observed back in 2009, setting a course for what might be dubbed "Life After Yucca" is going to require a Herculean effort, and Hercules-sized stacks of cash:

...To maintain (nuclear power in the) energy mix will require replacing and retrofitting the country's aging fleet of reactors, and to support those efforts without the prospect of Yucca Mountain, the new administration will have to act quickly to locate a waste storage project. That won't be easy. Congress will need to throw out all previous laws regarding nuclear waste disposal and start the site selection process from scratch. The Energy Department will need to tear up decades of contracts with nuclear energy providers and negotiate new terms for temporary storage. Legislators would then set to work investigating sites: Morris, Ill., where the government once experimented with a nuclear waste reprocessing operation? Oak Ridge, Tenn., the once-secret hub of the Manhattan Project? Those states would undoubtedly mount opposition of their own, just as they did in the 1980s...

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This is truly one of the more ridiculous stories I have ever read. I worked at Yucca Mt. on seismicity for several years and this story is totally without fact or research. Number one, their has been no recent 5.6 earthquake at Yucca Mt. The large events left the are many thousands of years ago to Death Valley. As the USGS seismologists stated in their report on possible large ground motions at Yucca, "the landscape of Yucca Mountain is remarkably unchanged in the past 1 million years..." And, regarding volcanoes, one can lie with numbers. The chance of volcanism at the site was force by the NRC to have a chance of slightly greater than that which meant it couldn't be considered - 1 chance in 1e-7, or 1 chance in 10 million. The potential for any environmental impacts from Yucca Mt. are virtually nil - read the license application if you want to be educated, don't read a rag like this written by people with no science or engineering education and an axe to grind.

Sarah Gilman

May 18, 2011 12:20 PM

Mark--Thanks for reading the piece. If you'd like to stick to the science, perhaps you'll consider the following.

1. The 5.6 earthquake beneath Yucca Mountain occurred in 1992 (within the last 20 years, as the article stated). That's pretty recent in geologic terms, and definitely worth worry. If you doubt the date, here's a link:http://www.state.nv.us/nucwaste/yucca/seismo01.htm

On the map, you'll note that there is a significant recent earthquake cluster just to the southeast of the proposed storage sites.

2) Yucca's application was supposed to evaluate the safety of the facility over at first 10,000 years, which EPA later raised to 1 million years. The 1 in 6,250 chance of igneous disruption over 10,000 years figure was widely circulated. It comes from a peer-reviewed report the DOE commissioned and is included in Yucca's license application (which you mentioned having read). Please see the report for reference (pdf): www.energy.gov/media/Igneous_Consequences_final_report.pdf

Another report from Los Alamos puts the risk at 1 in 7,000 over 10,000 years (link to pdf: www.fas.org/sgp/othergov/doe/lanl/pubs/00818055.pdf )

For context, you might ask seismologist what the chances of a 9.0 earthquake near Sendai (where that nasty tsunami happened) was before March 11. It was also nonzero. But not by much.

So as you conclude, Yucca Mountain is absolutely and completely safe... Unless you consider the facts involved rather than the politics influencing the debate.Then you might have some doubts.

Brad Robinson

May 19, 2011 08:00 PM

Thanks for the article as well as the thoughtful response to the first comment. Keep up the good work - I subscribed to the "rag" today after reading several excellent articles online.

Like my colleague, Mark Board, I worked on the Yucca Mountain project. I am a Ph.D seismologist and had lead contractor responsibility for planning and integrating the Yucca Mountain seismic hazard studies for many years.

There was not a magnitude 5.6 earthquake beneath Yucca Mountain in 1992. It was under Little Skull Mountain, 20 km from Yucca Mountain (http://pubs.usgs.gov/dds/dds-058/Ch_K.pdf). Yucca Mountain actually is remarkable for its lack of seismicity in a seismically active area, as evidenced by numerous precariously balanced rocks that would be knocked down by strong ground shaking. However, any competent geologist could glance at Yucca Mountain and tell you that it was formed by block faulting on geologic faults and, hence, is subject to earthquake ground motion. There has never been any question about that. The question is whether the potential ground motion can reasonably be characterized, whether the engineered systems can be designed to withstand that ground motion, and what the potential consequences are if the engineered systems should fail.

There is no question that the earthquake hazard at Yucca Mountain has reasonably been characterized. In fact, Yucca Mountain and the surrounding area is the most geologically intensively studied piece of real estate on the planet. The size of earthquakes is limited by the length of the causative geologic faults, and we know what the fault lengths are from detailed geologic mapping and numerous geophysical studies. The bottom line is that the seismic hazard at Yucca Mountain is moderate, with the potential for strong ground shaking dominated by magnitude 6.5-7.0 earthquakes occurring on local faults with recurrence times of tens of thousands to hundreds of thousands of years.

Designing for potential ground motion at Yucca Mountain is well within current engineering capabilities, and the consequences of failure would have no semblance to the disaster at Sendai. The spent fuel that would be shipped to Yucca Mountain would have been out-of-reactor long enough to no longer require special cooling. The waste forms to be handled are all rock solid--ceramic and metal in the case of spent nuclear fuel, and metal and glass in the case of defense high-level nuclear waste. Even if a spent fuel assembly were dropped inside a waste handling facility during an earthquake because of an engineering failure, the consequence would be radioactive material on the floor of a massive building with thick concrete walls. A mess to clean up, but no threat to the public. Once emplaced 1,000 feet underground in solid rock, the nuclear waste would be even more protected from earthquakes. The potential for earthquakes at Yucca Mountain is absolutely not a reason to abandon the site or a reason not to entomb all of the nation's waste in one location.

The estimated risk of volcanic disruption is, indeed, non-zero, but it is extremely small. The estimated hazard is barely above the level (one chance in 10,000 in 10,000 years) that the Nuclear Regulatory Commission considers to be the criterion for an event to be credible. Surprisingly, even if a volcano were to erupt right through Yucca Mountain, it is unlikely that much waste would be brought to the surface because of the narrow (1-2 meter) width of the feeder dikes that bring magma to the surface. In addition, most of the waste transported to the surface would be deposited locally and then covered by additional lava or volcanic ash. Admittedly, at other locations there would be essentially no volcanic hazard at all. However, the question is whether Yucca Mountain should be abandoned because of an extremely small risk for some other site, which, after spending billions of more dollars, might very well turn out to have some unique hazard of its own.

The quote in your article about the Nuclear Waste Policy Act of 1982 being created by Congress to shore up a faltering nuclear industry is nonsense. The Nuclear Waste Policy Act was enacted to meet a longstanding commitment of the federal government to take responsibility for the ultimate disposal of commercial nuclear waste. The Act was not needed because the industry was faltering; it was needed because the industry had been very successful and was producing a lot of waste that needed to be disposed. The federal government strongly encouraged the development of civilian nuclear power reactors and established the framework for such in the Atomic Energy Act of 1954. The government always planned to take ultimate responsibility for the disposal of spent nuclear fuel so that it could not be clandestinely diverted and reprocessed to produce weapons grade fissionable materials. The Atomic Energy Commission sponsored a study by the National Academy of Sciences on how best to dispose of nuclear waste. The NAS came to the same conclusion in 1957 (http://www.nap.edu/openbook.php?record_id=10294) that every other commission and study group in every country that has studied the issue has come to--the best way to dispose of nuclear waste is deep geologic burial. The Nuclear Waste Policy Act simply laid out the process for a repository to be sited, licensed, and paid for--by an assessment on the power produced by commercial nuclear reactors.

A quote in your article that is correct is that Congress' selection of Yucca Mountain was a technically informed political decision. Congress' 1987 amendment of the Nuclear Waste Policy Act to terminate repository studies in Washington state and Texas and to focus solely on Yucca Mountain was an extremely unfortunate development because it created the impression that Congress wanted to dump all of the nation's nuclear waste on Nevada. There was a preliminary study at the time that indicated that Yucca Mountain was the best of the three sites being considered, but it was hardly definitive. The Nuclear Waste Policy Amendments Act of 1987 poisoned the waters in Nevada. Since then Nevada has been inexorably opposed to Yucca Mountain and has used every means at its disposal, including grossly exaggerating the risks, to try to kill the project. Presidential politics and Harry Reid's ascendancy to the Senate Majority Leadership finally gave the state the leverage it needed to succeed, despite the fact that the Nuclear Waste Policy Act is still in force and requires the Department of Energy to license and develop a repository at Yucca Mountain.

It is my considered professional opinion that Yucca Mountain is not a perfect site, but it is good enough, meaning that it is well within current engineering capabilities to design and build a repository at Yucca Mountain that would safely isolate and contain spent nuclear fuel and defense high level nuclear waste. Yucca Mountain was chosen partially for political reasons, but we have a workable site that we have already invested billions of dollars in. Are we now just going to walk away for partisan political reasons and have no plan at all? That is exactly what Harry Reid and President Obama are asking us to do.

Sarah Gilman

Jun 06, 2011 10:45 AM

Fair enough Jerry -- And thanks for the well-articulated and reasoned response. I have a question about the 5.6 earthquake. You say it was 20 km away under skull mountain -- about 12 miles, yes? Wouldn't the shaking still be felt at Yucca? How much would the intensity dissipate?

Also, given that the court settled on a 1 million year safety window, wouldn't Yucca be disqualified at the outset? That you can engineer around a 5.6 earthquake in the short-term, I understand. But how can you engineer something to withstand a 5.6 for even 10,000 years, let alone 1 million? Forgive me if my questions sound daft, but to my laywoman's logic, that seems to defy common sense and border on the dangerously arrogant (not you, that is, but the idea that people are so all knowing and all powerful that their technological innovations are somehow immune to erosion and error, which it seems to me, is something we really can't risk with a waste site of such magnitude).

Judith Lewis Mernit

Jun 06, 2011 01:52 PM

Hi Jerry and Mark --

I'm not sure I understand what the points of disagreement are here, or why words like "nonsense" and "ridiculous" are getting thrown around so recklessly. There's simply no disagreement that the area around Yucca Mountain is seismically active. It's a hoary argument. You can keep turning the perspective globe around and around and explaining it different ways, but earthquakes happen there, and the DOE's own literature acknowledges there exists there a threat of igneous disruption. Period. End of story. "Good enough" isn't good enough when you're talking about millions of years of storage.

I think we all can agree that what happened in Japan was off the scale of any other confluence of disasters we've known. But now that it's been brought up, that's precisely the point: No one expected a quake of that magnitude to be followed by such a devastating tsunami. All scientists knew was that earthquakes happen there. Seismology is a humbling profession, and those who refuse to be humbled by geological time put us all in peril.

As for that "very successful" nuclear industry: By 1982, the nuclear industry was effectively dead. No orders for new reactors had been made since the mid-1970s; a few had already been canceled. There were a lot of reasons for its failure, most of them economic, but at least one was the industry's inability to deal with what was described in Fortune magazine in 1979 as a "constipation" in the industry -- the waste disposal problem. Contrary to any "longstanding commitment of the federal government," the nuclear industry had early on anticipated taking care of a substantial amount of it own waste problem -- utilities thought they'd be able to make money on it, either by offering storage facilities or reprocessing. As the late Fred C. Shapiro writes in Radwaste, his thorough and prescient analysis of the growing problem back in 1981, the acting administrator of the Energy Research and Development Administration in 1977, Robert Fri said in 1977 that the waste problem "has deep historical roots which go back to the time ten or so years ago when the Atomic Energy Commission took the view that once . . . reactors had been developed, much of the rest of the fuel cycle . . . would come about by natural industry action." Reprocessing proved dangerous, storage expensive, and so the industry turned to the federal government for what was, essentially, a bailout.

Shapiro, who died in 1993, revisited the waste problem again in 1987, when he documented step-by-step in the New Yorker magazine the deeply politicized process (and holiday-season rush job) that led to the selection of Yucca Mountain -- highly recommended reading. Many geologists and nuclear engineers have since recommended dozens of better solutions (such as those pursued in Sweden and Finland, which I wrote about in the original 2008 article), which the President has created a Blue Ribbon panel to address. We not only owe this better solution to the residents of Nevada in general and the nearby Amargosa Valley in particular, but to future generations on this planet, whose safety and security is at risk should we continue to politicize what should be purely scientific decisions.

Judith Lewis Mernit

Jun 06, 2011 02:00 PM

Note: I should have said "the nuclear industry in the United States was effectively dead." Other countries, such as France and Japan, continued to build reactors. But they only did so with robust government support and, in some cases, control.

Jerry King

Jun 06, 2011 03:35 PM

Sarah, yes, the shaking from the Little Skull Mountain earthquake was felt at Yucca Mountain. Unfortunately, there were no strong-motion recording instruments at Yucca Mountain at the time. However, we know from the study of many thousands of earthquakes world-wide and from recordings of Little Skull Mountain aftershocks that the ground motion at Yucca Mountain likely was attenuated by 50-75%, compared to a location right on Little Skull Mountain. A probabilistic earthquake hazard assessment, as was done for Yucca Mountain, takes into account the local faults that could produce earthquakes, estimates of the frequency of earthquake occurrence and maximum magnitudes, and the attenuation of ground motion with distance, to come up with a total, integrated assessment of the potential to exceed a particular ground-motion measure, like peak acceleration, over a defined period of time. This hazard assessment is then used to define the seismic design requirements that any engineered facilities must meet.

The surface facilities at Yucca Mountain that would receive and prepare waste for underground emplacement do not have to be designed for 10,000 or 1 million years. They have a design lifetime of 100 years. They would be decommissioned when the repository is full, and the entrances to the repository would be backfilled and sealed. At that point, the repository would consist of a network of deeply buried tunnels housing many large metal canisters of waste, covered by titanium shields to protect the canisters from rockfall and to divert any dripping water.

I share your skepticism about designing any facility to last 10,000 years, let alone 1 million years. We cannot project the performance of Yucca Mountain, or any repository, for that period of time with a lot of confidence. (I suppose I should state here that I retired from Yucca Mountain in 2005 and am speaking strictly for myself.) Our computer models say it will work, but the uncertainties are large. The law requires that "reasonable assurance" be demonstrated for a license to be granted by the Nuclear Regulatory Commission. The scuttlebutt is that the NRC staff was ready to accept the license application when it was pulled by the Department of Energy, at the direction of the Obama administration. If the application had been accepted, it would have been litigated in a licensing hearing with attorneys from the State of Nevada and other admitted parties questioning every calculation and assumption. Unless the courts force the Obama administration to comply with the requirements of the Nuclear Waste Policy Act, we will never know if the license application would have survived the hearing process.

Sarah Gilman

Jun 06, 2011 03:40 PM

Jerry--That's a good point. And it's one that Judith made well in her story: If Yucca really is unacceptable, then you would hope the licensng process would weed it out as an option (except it is listed as the ONLY option). I wonder though, whether that process itself is truly immune to politics?

Jerry King

Jun 06, 2011 07:22 PM

Judith, you are right that I used the term "nonsense" too loosely. You also provided information I was not aware of, and I think you for that. Nevertheless, I think it is unfair to call the Nuclear Waste Policy Act a "bailout." Far from being bailed out, the nation's nuclear utility companies have been screwed by the government. They have paid more than $10 billion dollars into the Nuclear Waste Fund, to pay for a repository, and have gotten absolutely nothing in return.

There is a perceptual disconnect between most nuclear scientists and engineers and the public regarding the hazard posed by spent nuclear fuel. Yes, it is extremely radioactive and highly toxic and, yes, some of it remains radioactive for millions of years. However, there are lots of other industrial wastes (e.g., lead, cadmium, selenium, arsenic, cobalt, mercury) that are highly toxic, have the potential to contaminate ground water, and never decay, and we do not impose disposal requirements on such wastes that are anything like the requirements for the disposal of radioactive wastes. The disparate approaches are not due to huge differences in the hazards posed by these waste forms. Rather, they are driven by the public's extreme fear of radiation, which gets translated in our representative democracy to extreme regulatory requirements. Unfortunately, the result is not just an extra burden on the nuclear industry. One result is the expenditure of billions of dollars to avoid even a single death due to radiation exposure. This is money that cannot be spent, with much greater cost effectiveness, to mitigate other public heath issues. Another result is political gridlock in which nothing at all gets done. That's where we are now with Yucca Mountain. It cannot possibly be safer for the nation's spent nuclear fuel to be scattered around the country in dozens of different locations than to be housed in tunnels 1,000 feet below the crest of Yucca Mountain.

I agree with your admonition to remain humble in the face of deep geologic time--it is my job to do so. I expressed my skepticism of projecting the performance of any repository for a million years earlier in this thread. However, humility is no reason not to rationally examine relative hazards. All nuclear power plants have extremely hot and energetic reactor cores that must be actively cooled, even when the nuclear chain reactions have ceased, to prevent a meltdown. As we saw at Fukushima, fresh spent fuel that is stored in cooling ponds also has to be cooled, else it can get so hot it can catch on fire. The fuel that would be shipped to a repository would be cool enough that these failure modes simply would not exist. One can imagine and postulate other events that could, conceivably, scatter repository waste into the environment, including fires from sources other than the fuel itself, airplane crashes, terrorist attacks, even, in the case of Yucca Mountain, an extremely low but non-zero chance of a volcanic eruption. However, all of these scenarios would result in, at worst, localized contamination and every scenario (even the volcano to some extent) can be mitigated by appropriate design features and operational procedures.

I need to emphasize the last point. Failure of a repository at Yucca Mountain would not be the end of the world. Your assertion that the safety and security of future generations on this planet are at risk if we proceed with Yucca Mountain is extreme hyperbole. The worst case outcome from a waste-handling accident in one of the surface facilities would be localized contamination of a remote and unpopulated area. The likely worst-case outcome of a long-term failure of the repository would be contaminated groundwater beneath Amargosa Valley and Ash Meadows, thousands of years from now. Neither scenario is acceptable, and billions have already been spent to make sure they would not happen, but neither scenario would be a global or even regional catastrophe. Of course, we cannot know what it is that we do not know, and we cannot guarantee there will not be unexpected outcomes. However, any decision regarding waste disposal, no matter how long delayed, must be made in the face of uncertainty, and currently available information indicates we would all be safer if the nation's spent nuclear fuel were consolidated beneath Yucca Mountain.

However, that still leaves open the question of whether there is even a better solution than disposing spent fuel at Yucca Mountain. I think there is. We should not bury and walk away from an enormous, non-fossil-fuel, energy resource. Spent nuclear fuel can be reprocessed to recover the unburned uranium-235 and the fission-product plutonium-239 and used to make new nuclear fuel. There would still be an ultimate waste product that would require deep geologic disposal, but much less of it, and with less waste heat to deal with. Unfortunately, the Carter administration (not the nuclear industry) decided not to reprocess the nation's spent nuclear fuel because of the up-front costs, political opposition, and fear that the separated plutonium-239 could somehow be diverted and used to make nuclear weapons. I would love to see that decision reversed. If it were up to me, I'd amend the Nuclear Waste Policy Act, license Yucca Mountain to store spent fuel temporarily, aggressively pursue reprocessing, and spend the next 50 years or so doing studies to confirm that nuclear waste can safely be disposed at Yucca Mountain for the very long term.

Wendell Duffield

Jun 09, 2011 08:54 AM

I'm a PhD geologist, specializing in volcanology. I had a 30-year career with the U.S. Geological Survey, retired from the USGS in 1997, and have ever since been an Adjunct Professor in the geology program at Northern Arizona University, Flagstaff. During the late 1990s, I was a member of a panel of volcano experts convened to assess the probability that an igneous event would disrupt the Yucca Mountain storage site. As other comments have already pointed out, that probability is small. But it is a real positive number, and the potential impact to the site is large.

Volcanic eruptions can occur across a broad spectrum of sizes and degrees of violence. The panel I was part of was instructed to ignore a violent type called phreato-magmatic, the justification being that magma would not encounter shallow groundwater at Yucca. That justification may be valid today, and perhaps even into the somewhat-clearly foreseeable future if climate modellers are correct. But I have doubts that such models are very accurate for ten thousand years into the future, to say nothing about one million years.

For a quick education into what a phreato-magmatic eruption might do at Yucca, one has only to visit Ubehebe Crater at the north end of Death Valley. And that big hole blasted in the ground there happened only a couple thousand years ago.

Jerry King

Jun 09, 2011 02:38 PM

The exclusion of a phreato-magmatic eruption at Yucca Mountain as a credible event is not just based on long-term climate models. It is based mostly on the fact that there is no geologic, geochemical, or biological evidence of a shallow groundwater table at Yucca Mountain since the formation of the mountain, including past ice ages in which there was considerably more precipitation than today. The groundwater recharge conditions at Ubehebe are not the same as those at Yucca Mountain, and Ubehebe is not a good analog for predicting the potential effects of an igneous intrusion at Yucca Mountain.

Wendell Duffield

Jun 09, 2011 06:54 PM

Jerry. As recently as about 20 years ago, there was credible geologic evidence that the youngest (80 ka) volcanic eruption near Yucca included a major phreato-magmatic phase. Subsequent geologic mapping includes phreatomagmatism as part of that eruption. Who knows what the next round of geologic mapping will "conclude". Meanwhile, there are vast regions of the lower 48 states where no major earthquakes or volcanic eruptions have occurred for the most recent 10s of millions of years, if not much longer. So why would one chose Yucca as the site for storage of long-lived radioacitve waste? Even if one wanted to use the Yucca Mtn region, why locate the site to be as close as possible to the half dozen of vocanic eruptions that have occurred during the past million years, the most recent being only 80 ka years ago? I am cynical enough and scientifically savy enough to see lots of politics in the decision to select Yucca

Jerry King

Jun 10, 2011 12:37 PM

Wendell, prompted by your comment, I went back and reviewed the Project's findings on phreatomagmatism. The evidence you are referring to is a 1-meter thick deposit at the Lathrop Wells cinder cone that geologists have attributed to a phreatomagmatic phase early in the last eruption sequence, which occurred about 80,000 years ago. However, the deposit is very limited and is estimated to comprise only 0.01% of the total volume of lava and tephra that was erupted. I do not think that that can fairly be described as a "major" phreatomagmatic phase and it certainly is not comparable to the catastrophic phreatomagmatic explosion that created Ubehebe crater.

As you probably know, the issue of a rise in groundwater at Yucca Mountain was studied to death because former DOE scientist Jerry Szymanski claimed that there was evidence of hydrothermal upwelling at Yucca Mountain. After exhaustive studies and numerous peer reviews, including an independent review by the National Academy of Sciences, the Project found that there was no evidence of hydrothermal upwelling and that the water table could rise by 50 to 130 meters under extremely wet climatic conditions based on mineralogic data, isotopic data, discharge deposit data, and hydrologic modeling analysis. Even with this rise, the groundwater table would still be deep and well below the level at which waste would be emplaced. Again, with no evidence that there ever has been or could be a shallow groundwater table at Yucca Mountain, the Ubehebe scenario is not credible.

You ask why one would chose Yucca Mountain when other sites could be chosen in the region that would be further from the volcanic field in Crater Flat. The site was not chosen arbitrarily. It was singled out because of the extraordinarily deep water table, which provides the opportunity to deeply bury waste but still keep it dry. At all other candidate sites considered in the U.S., and at all other sites being considered by other countries for their own waste disposal, waste would be emplaced below the groundwater table and, eventually, would be completely submerged. Further investigation revealed two other highly attractive features of Yucca Mountain. First, the volcanic tuff host rock is not significantly mineralized and is not an attractive target for mineral resource exploration. It is very unlikely that a repository at Yucca Mountain would be inadvertently disturbed by the exploration activities of future generations. Second, the tuff itself is easily mined but strong enough to provide stable underground openings. Finally, Yucca Mountain is far enough removed from other locations on the Nevada Test Site that it would not interfere with nuclear weapons testing, if the U.S. were to decide that such testing needs to resume.

Steve Snyder

Jun 10, 2011 04:47 PM

I suggest we get beyond an overt paranoia about plutonium theft by terrorists, while at the same time actually funding more than adequate security at reactors, and build all breeder-type reactors from here on out, and thereby reduce nuclear waste.

paul hoornbeek

Jun 11, 2011 07:26 AM

I live just over the hill from YM, feel earthquakes weekly and drive past cinder cones daily. But what concerns me more is transporting materials to the site. Safe as YM might it might not have been, the stuff has to get there on trucks, which roll over and catch fire hereabouts fairly regularly.